Iysas is an indirect Quranic name for girls that means “increase”, “plenty”, “splendor”. It literally is Ithath (with the “th” as in “thing”), but for ease of pronunciation Arabs say it as Iysas. It is derived the A-Th-Th Quranic root (greatness, splendor), which the Quran uses in the word athath (wealth, riches, means of comfort, furnishings).